The Seekers have a fabulous post on writing a query letter, include samples, and links. This is a two-parter, so be sure to catch both of them.
I found one observation particularly interesting. People are learning how to produce a dynamite query letter, but not paying as much attention to their novels. Hmm - a bit of cart before the horse here?
Dee Stewart, at The Master's Artist, gives 10 ways to promote your writing through the holidays. Check it out. Have a great weekend!